The word "transonic" is correct in written English.
It is used to describe speeds that are close to the speed of sound, typically in the context of aerodynamics or fluid dynamics. Example: "The aircraft was designed to operate efficiently in transonic flight conditions." Alternatives include "near-sound speed" or "subsonic to supersonic."
Soon Andrea has an epiphany and starts firing correct answers, getting, in KhanAcademy's jargon, a "badge", then going "transonic".
The X-15 established an extensive database in transonic and supersonic flight (up to five times the speed of sound) and revealed vital information concerning the upper atmosphere.
Tunnels are classified according to airflow velocity: subsonic (up to Mach 0.8), transonic (Mach 0.8 1.2), supersonic (Mach 1.2 6), hypersonic (Mach 6 12), or hypervelocity (above Mach 12).
The solution involved adding volume to the fuselage ahead of and behind the wing and reducing it near the wing and tail, to create a cross-sectional area that more nearly approximated the ideal area to limit transonic drag.
These fighters operated at high subsonic speeds, but the competitive pressures of development required aircraft that could operate at transonic and supersonic speeds.
Wind tunnels are classified as low-speed or high-speed; they are further classified as subsonic (80 percent of the speed of sound), transonic (about the speed of sound), supersonic (up to 6 times the speed of sound), hypersonic (6 to 12 times the speed of sound), and hypervelocity (over 12 times the speed of sound).
It is, however, quite inefficient at transonic flight speeds and is completely ineffective at subsonic velocities.
The F-86 was built with the wings swept back in order to reduce transonic drag rise as flight speed approached the sound barrier, and it was capable of exceeding the speed of sound in a dive.
Supersonic flight offered the aeronautical engineer new challenges in propulsion, structures and materials, high-speed aeroelasticity, and transonic, supersonic, and hypersonic aerodynamics.
At transonic flight speed this pressure ratio is almost 2 1, so that the engine's compressor may be built to provide that much less pressure where peak pressure is otherwise limiting.
Moving up in the spectrum of flight speeds to the transonic regime Mach numbers from 0.75 to 0.9 the most common engine configurations are turbofan engines, such as those shown in Figures 4 and 5.
